Traditional exposure of photographic paper in a photofinishing apparatus comprises the optical exposure of a photographic film negative onto photographic paper. Modifications to this image can be made by using a photographic mask which allows cropping or additional information to be rendered on the photosensitive material. In a typical photofinishing lab, the images are provided at a high rate onto the photosensitive paper in order to provide a low cost, high quality product. An example of a high speed optical photographic printer is the Clas 35 Printer sold by the Eastman Kodak Company. This device is capable of exposing approximately eight images per second.
While the foregoing printer is able to produce high quality prints at a relatively low cost, there are various drawbacks to such a system. Such devices are limited in the amount of enhancement that can be made to the print. Additionally, such devices are not suitable for providing index prints along with each individual order being processed. Typically, when index prints are required, information that has been obtained during the scanning step is forwarded on to a separate digital printer wherein the index print is produced. This obviously requires additional equipment and collation of the index print and the print order which it is associated with.
There has been suggested various methods for digitally rendering images on photosensitive material. For example, there has been suggested CRT (cathode ray tube printers) for printing of photographic paper. It has also been suggested the use of LEDs, such as disclosed in U.S. Ser. No. 08/123,839, entitled "Method and Apparatus for Exposing Photosensitive Media with Multiple Light Sources", filed Sep. 20, 1993, in the names of Douglas H. Smith, John F. Carson, Roy B. Ference, and Kevin J. Appel. However, a significant drawback with such devices is the amount of time necessary to produce a single image. Typically, CRT printers take about 4 to 8 seconds to produce a single image and LED printers take substantially longer periods of time. With respect to high speed photographic printing, such speeds are very slow.
There has also been suggested in the prior art the printing of photographic photosensitive material through the use of liquid crystal display devices. For example, U.S. Pat. No. 4,810,058 discloses a color liquid crystal device for printing images onto photosensitive material. However, in this device the liquid crystal display (LCD) is moved between three separate positions in order to provide exposure of the image. Due to the relative movement of the LCD, the quality in the image suffers significantly and requires a significant amount of time in which to produce the image an in-line printer that can provide the index print along with the order for which it is associated.
Applicants have invented a high speed color photographic printer which provides high quality color images at a high rate. Additionally, the photographic printer can be used in-line with conventional optical printers so that index prints can be made directly in-line and adjacent the order to which it is associated.